// download.js v4.2, by dandavis; 2008-2016. [CCBY2] see http://danml.com/download.html for tests/usage
// v1 landed a FF+Chrome compat way of downloading strings to local un-named files, upgraded to use a hidden frame and optional mime
// v2 added named files via a[download], msSaveBlob, IE (10+) support, and window.URL support for larger+faster saves than dataURLs
// v3 added dataURL and Blob Input, bind-toggle arity, and legacy dataURL fallback was improved with force-download mime and base64 support. 3.1 improved safari handling.
// v4 adds AMD/UMD, commonJS, and plain browser support
// v4.1 adds url download capability via solo URL argument (same domain/CORS only)
// v4.2 adds semantic variable names, long (over 2MB) dataURL support, and hidden by default temp anchors
// https://github.com/rndme/download

(function (root, factory) {
	if (typeof define === 'function' && define.amd) {
		// AMD. Register as an anonymous module.
		define([], factory)
	} else if (typeof exports === 'object') {
		// Node. Does not work with strict CommonJS, but
		// only CommonJS-like environments that support module.exports,
		// like Node.
		module.exports = factory()
	} else {
		// Browser globals (root is window)
		root.download = factory()
  }
}(this, function () {
	return function download (data, strFileName, strMimeType) {
		var self = window // this script is only for browsers anyway...
			var defaultMime = 'application/octet-stream' // this default mime also triggers iframe downloads
			var mimeType = strMimeType || defaultMime
			var payload = data
			var url = !strFileName && !strMimeType && payload
			var anchor = document.createElement('a')
			var toString = function (a) { return String(a) }
			var myBlob = (self.Blob || self.MozBlob || self.WebKitBlob || toString)
			var fileName = strFileName || 'download'
			var blob
			var reader
			myBlob = myBlob.call ? myBlob.bind(self) : Blob

		if (String(this) === 'true') { // reverse arguments, allowing download.bind(true, "text/xml", "export.xml") to act as a callback
			payload = [payload, mimeType]
			mimeType = payload[0]
			payload = payload[1]
		}

		if (url && url.length < 2048) { // if no filename and no mime, assume a url was passed as the only argument
			fileName = url.split('/').pop().split('?')[0]
			anchor.href = url // assign href prop to temp anchor
		  	if (anchor.href.indexOf(url) !== -1) { // if the browser determines that it's a potentially valid url path:
        		var ajax = new XMLHttpRequest()
        		ajax.open('GET', url, true)
        		ajax.responseType = 'blob'
        		ajax.onload = function (e) {
				  download(e.target.response, fileName, defaultMime)
				}
        		setTimeout(function () { ajax.send() }, 0) // allows setting custom ajax headers using the return:
			    return ajax
			} // end if valid url?
		} // end if url?

		// go ahead and download dataURLs right away
		if (/^data\:[\w+\-]+\/[\w+\-]+[,;]/.test(payload)) {
			if (payload.length > (1024 * 1024 * 1.999) && myBlob !== toString) {
				payload = dataUrlToBlob(payload)
				mimeType = payload.type || defaultMime
			} else {
				return navigator.msSaveBlob // IE10 can't do a[download], only Blobs:
					? navigator.msSaveBlob(dataUrlToBlob(payload), fileName)
					: saver(payload) // everyone else can save dataURLs un-processed
			}
		}// end if dataURL passed?

		blob = payload instanceof myBlob
			? payload
			: new myBlob([payload], { type: mimeType })

		function dataUrlToBlob (strUrl) {
			var parts = strUrl.split(/[:;,]/)
			var type = parts[1]
			var decoder = parts[2] == 'base64' ? atob : decodeURIComponent
			var binData = decoder(parts.pop())
			var mx = binData.length
			var i = 0
			var uiArr = new Uint8Array(mx)

			for (i; i < mx; ++i) uiArr[i] = binData.charCodeAt(i)

			return new myBlob([uiArr], { type: type })
		 }

		function saver (url, winMode) {
			if ('download' in anchor) { // html5 A[download]
				anchor.href = url
				anchor.setAttribute('download', fileName)
				anchor.className = 'download-js-link'
				anchor.innerHTML = 'downloading...'
				anchor.style.display = 'none'
				document.body.appendChild(anchor)
				setTimeout(function () {
					anchor.click()
					document.body.removeChild(anchor)
					if (winMode === true) { setTimeout(function () { self.URL.revokeObjectURL(anchor.href) }, 250) }
				}, 66)
				return true
			}

			// handle non-a[download] safari as best we can:
			if (/(Version)\/(\d+)\.(\d+)(?:\.(\d+))?.*Safari\//.test(navigator.userAgent)) {
				url = url.replace(/^data:([\w\/\-\+]+)/, defaultMime)
				if (!window.open(url)) { // popup blocked, offer direct download:
					if (confirm('Displaying New Document\n\nUse Save As... to download, then click back to return to this page.')) { location.href = url }
				}
				return true
			}

			// do iframe dataURL download (old ch+FF):
			var f = document.createElement('iframe')
			document.body.appendChild(f)

			if (!winMode) { // force a mime that will download:
				url = 'data:' + url.replace(/^data:([\w\/\-\+]+)/, defaultMime)
			}
			f.src = url
			setTimeout(function () { document.body.removeChild(f) }, 333)
		}// end saver

		if (navigator.msSaveBlob) { // IE10+ : (has Blob, but not a[download] or URL)
			return navigator.msSaveBlob(blob, fileName)
		}

		if (self.URL) { // simple fast and modern way using Blob and URL:
			saver(self.URL.createObjectURL(blob), true)
		} else {
			// handle non-Blob()+non-URL browsers:
			if (typeof blob === 'string' || blob.constructor === toString) {
				try {
					return saver('data:' + mimeType + ';base64,' + self.btoa(blob))
				} catch (y) {
					return saver('data:' + mimeType + ',' + encodeURIComponent(blob))
				}
			}

			// Blob but not URL support:
			reader = new FileReader()
			reader.onload = function (e) {
				saver(this.result)
			}
			reader.readAsDataURL(blob)
		}
		return true
	} /* end download() */
}))
